2-lower alkoxy-2-ethylbutyrylurea and method of preparing same



United States Patent Z-LOWER ALKOXY-Z-ETHYLBUTYRYLUREA AND METHOD OF PREPARING SAME Otis E. Fancher and Dale A. Staulfer, Elkhart, Ind., assignors to Miles Laboratories, Inc., Elkllart, Ind., a corporation of Indiana Application February 24, 1954, Serial No. 412,379

4 Claims. (Cl. 260-553) No Drawing.

This invention relates to derivatives of Z-ethylbutyrylurea which have been found to possess excellent physiological activity as hypnotics and sedatives. More particularly, this invention relates to 2-alkoxy-2-ethylbutyrylureas which can be produced by reacting a 2-halo-2-ethylbutyrylurea with an alkali metal alcoholate as indicated in the following reaction:

CzHa OONHCONH: C$5/CONHCONH2 ROM /C\ C2115 X 02H: OR

EXAMPLE I 2-meth0xy-2-ethylbutyrylurea 2-bromo-2-ethylbutyrylurea (47.4 g., 0.2 mole) and 150 ml. of methanol were stirred while sodium methoxide (10.8 g., 0.2 mole) was added over a period of thirty 2,723,293 Patented Nov. 8, 1955 minutes. After the spontaneous exothermic reaction was over, the mixture was refluxed for three hours. The methanol was distilled 01f under reduced pressure and ml. of water was added. After acidification with hydrochloric acid the solid material was collected and crystallized from ligroin, B. P. 85-100, as colorless crystals which melted at 133l34. Percent found: 15.01; calculated for CaHisNaOs: 14.88%.

EXAMPLE II 2-isopropoxy-2-ethylbutyrylurea A quantity of 5.75 g. (0.25 mole) of sodium was dissolved in 250 ml. of dry isopropyl alcohol. 59 g. (0.25 mole) of 2-bromo-2-ethylbutyrylurea was added and the mixture was refluxed for 2 hours. The hot solution was filtered to remove sodium bromide. The solid which separated was filtered off, and the filtrate was diluted with water. A heavy oil separated and solwly solidified.

The first solid after recrystallization from alcohol proved to be Z-ethylcrotonylurea, M. P. 190-493. The second solid after crystallization from ligroin, B. P. 85- l00, melted at -115. Percent N found: 13.11; calculated for Z-isopropoxy-2-ethylbutyrylurea, C10H20N2O3: 12.95%. After one more crystallization from ligroin this material melted at 114-ll6; percent N found: 12.86.

Having thus described our invention, we claim:

1. A 2-alkoxy-Z-ethylbutyrylurea having the formula wherein R is a lower alkyl.

2. 2-methoxy-2-ethylbutyrylurea.

3. 2-isopropoxy-2-ethylbutyrylurea.

4. A method of producing a 2-alkoxy-2-ethylbutyrylurea which comprises reacting a 2-halo-2-ethylbutyrylurea with an alkali metal alcoholate prepared from a lower alkanol.

No references cited. 

1. A 2-ALKOXY-2-ETHYLBUTYRYLUREA HAVING THE FORMULA
 4. A METHOD OF PRODUCING A 2-ALKOXY-2-ETHYLBUTYRYLUREA WHICH COMPRISES REACTING A 2-HALO-2-ETHYLBUTYRYLUREA WITH AN ALKALI METAL ALCOHOLATE PREPARED FROM A LOWER ALKANOL. 